So you're a worrier. In the old cartoon "Top Cat", which featured various moggies in unlikely scenarios as they cadged food or affection from the local back alley, there was a character just like you. He always worried. If "Top Cat" hatched a plan to raid the Fish delivery van then Cat Worrier would find some fault or think that "it could never work". Like the plots needs a negative pivot. Just made the plans more triumphant. This was around in the 70's but it's the same deal with modern cartoons. For high anxiety watch any episode of Power Rangers !
But.................when the worrying's done and the result is better than anticipated you will be worry free or even a bit happy. Lots of people worry and with good reason. In the 3rd world the worry would be about "will I eat today ?" but in the Western World it is "will I get that new ipad ?".
It's hard to enjoy anything if you're anxious. Maybe the anxiety, if "everything is so amazing" is to do with having a parent that forced thought you into feeling low self esteem and that nothing would ever be good enough ? Maybe you have a sister that is married with 16 children and you a merely a single and you better watch out because the clock is ticking. Wow ! Families are great at just feeding us anxiety.
If you can feel valued you will worry less. If you worry less you will feel more valued. Sometimes life does "come crashing down" but that doesn't mean you're out of the game. Most of the amazing adventures (Shackleton - polar explorer, Hilary - something to do with Everest, Kontiki Expedition - traversing oceans on a raft to prove migration and 800 yr Heads Up to Boat People, England winning the World Cup Soccer in 1966 when Bobby Charlton was captain, etc) have all had disasters and failings.
But the human spirit endures. Getting through the next hour is enough to worry about. Being happy in adversity is a bit tricky. Try accepting where you're at now without putting heaps of pressure on the next part of your life. Sometimes time plods. I have worried less since I decided not to wear a watch 30 yrs ago. Simple. And, with a bit of practise, it's easy to still be able to tell the time.